Trigonalys erythrocephala Santos & Aguiar, 2012

Santos, Bernardo F., Aguiar, Alexandre P. & Tedesco, Anazelia M., 2012, Trigonalidae (Hymenoptera) from cacao agroforestry systems in northeastern Brazil, with two new species of Trigonalys Westwood, Journal of Hymenoptera Research 25, pp. 19-34 : 22-25

Trigonalys erythrocephala Santos & Aguiar sp. n. Figs 3-12

Holotype

♀, Brazil, Bahia, Uruçuca, Fazenda Bom Jardim, Pt 5, 25.XI.2002, Malaise trap, J. Cardoso & J. Maia (UFES). Mounted on a triangle point; in good condition.

Paratype

♀, same data as holotype, except Pt 7, 23.XI.2002 (CEPLAC).

Diagnosis.

Frons, most of vertex, and temple, reddish brown; metasomal armature of sternum III conspicuous, Y-shaped; supra-antennal elevation stout, conspicuous; hind coxa dorsally somewhat concave longitudinally, forming two longitudinal edges on each side, throughout its length, dorso-mesal portion strigate; legs entirely dark brown; fore wing nearly uniformly infuscate, except slightly darker along anterior margin.

Description.

Holotype: body length 8.5 mm; fore wing length 7.4 mm.

Head ( Figs 1, 2 - 4 ). Mandible covered with long and moderately dense setae; ventral tooth of right mandible distinctly longest and narrowest, median teeth length subequal, [dorsal tooth not visible; mandibles closed, left mandible not observed]. Clypeus 2.28 × as wide as maximum length, laterally distinctly pilose, centrally glabrous, faintly punctate. Inner margin of eyes subparallel; interocular distance at narrowest level 1.17 × maximum eye height. Antenna with 25 flagellomeres, about 1.4 × the lateral length of mesosoma; intertoruli distance slightly longer than distance from torulus to inner margin of eye. Supra-antennal elevation conspicuous, laterally a sharp carina ( Fig. 5 ), between antennae with rounded border. Frons pilose, densely punctate; punctation at median portion dorsally sparse, feeble; frons medially with a subtle longitudinal depression; area around and between ocelli slightly concave ( Fig. 5 ). Vertex shiny, densely pilose, moderately punctate. Gena maximum width in lateral view 0.83 × maximum eye height, finely punctate, densely pilose, particularly at ventral 0.4. Occipital carina conspicuous, widest dorsally, narrowest ventrally.

Mesosoma ( Figs 3, 7-8 ). Densely pilose. Pronotum: anterior, neck-shaped portion moderately long, laterally transversally wrinkled ( Fig. 3 ), centrally distinctly concave, anterior margin wide, polished; pronotum lateral area dorsally densely punctate, ventrally sparsely punctate, its posterior margin with distinct longitudinal wrinkles; central portion of lateral area intensely concave, anteriorly with stout oblique carina ( Fig. 10 ). Mesoscutum and scutellum deeply punctate ( Fig. 7 ), almost punctate-reticulate; notaulus deeply impressed, with distinct transverse wrinkles inside; median lobe of mesoscutum progressively raised from lateral lobes, until quite detached at anterior end; median lobe and scutellum with shallow but distinct mid-longitudinal sulcus; scutellum anteriorly with distinct longitudinal crenulation, centrally distinctly projected, subpyramidal; posterior margin shiny and impunctate. Hypoepimeron distinctly projected, subpyramidal, punctate, except small posterior area shiny and impunctate; scrobal sulcus distinct, somewhat crenulate; mesopleuron otherwise mostly punctate to areolate-punctate. Mesopleural suture dorsally deeply carinate. Metanotum (a narrow yellow stripe; Fig. 7 ) anteriorly moderately punctate, posteriorly impunctate; metapostnotum (the subsequent black stripe) rugose. Metapleuron finely punctate. Transverse sulcus at base of propodeum as long as metapostnotum, shallow, finely crenulate ( Fig. 8 ). Propodeum densely pilose, laterally setae distinctly longer than centrally; antero-lateral corners longitudinally rugose, otherwise mostly punctate-areolate or areolate-rugose, centrally and posteriorly in concentric patterns, anteriorly with shiny and almost impunctate area; propodeal spiracle covered by prominent, tubercle-like flap. Propodeal foramen somewhat M-shaped ( Fig. 8 ). Hind coxa with two sharp lateral angles extending throughout its length ( Fig. 11 ), dorso-mesal portion strigate.

Wings. Fore wing vein M arising almost opposite to crossvein 1cu-a; crossvein 2m-cu distinctly sinuous, with bulla on anterior 0.75; crossveins 2r-m and 3r-m almost straight. Second submarginal cell distinctly petiolate; third submarginal cell subtrapezoidal, slightly wider than high.

Metasoma. Densely covered with short setae. Tergum I slightly concave, short and broad, trapezoidal in dorsal view; 0.45 × as long as maximum width, apical widt h 1.48 × basal width; mid-basally with a few distinct, somewhat concentric rugulosities; posterior margin nearly straight across, with large but shallow punctures. Terga II-V and sterna I-V densely punctate, densely covered with short setae. Metasomal armature developed on sternum III as single, Y-shaped, very sclerotinized projection, with pointed corners ( Fig. 9 ). Ovipositor sheath shaped as a curved beak, laterally with longitudinal carina ( Fig. 9 ).

Color. Head mostly reddish brown, body mostly black, with yellowish marks. Head: antenna basally ferruginous, otherwise brown or nearly so; palpi dark brown; ventral margin of mandible, teeth apex, clypeal borders, small marks dorsad to toruli, subtriangular mark on vertex and most of gena and occiput, black; mandible except apex, clypeus, area around ventral 0.7 of eye and small marks on gena and around subtriangular black area, pale yellow; subapical portion of mandible between yellow and black areas, frons, most of vertex, and area around dorsal 0.3 of eye, reddish brown; vertex with dark, triangular mark behind ocelli, extending and narrowing posteriorly until it reaches occipital carina; a yellow stripe along each side of dark triangle. Mesosoma: black, except pale yellow to yellow on pronotal collar, dorsal margin of pronotum, margins of median mesoscutal lobe, alongside notaulus, lateral longitudinal marks on scutellum, axilla, metanotum, small central spot on mesopleuron, on apex of pyramidal projection, and J-shaped mark on each side of propodeum. Prominence of propodeal spiracle ferruginous. Legs apically to coxae dark brown. Wings slightly infuscate, fore wing darker towards anterior margin. Metasoma: black; all terga and sterna with posterior pale yellow stripes, on terga II-V also extending laterally; tergum VI brownish; sternum V almost entirely pale yellow.

Male. Unknown.

Variation.

Holotype with terga II-IV showing anomalous development ( Fig. 12 ). Paratype body length 9.3 mm; fore wing length 7.7 mm; yellow marks on gena and near subtriangular black mark at vertex, very subtle; propodeum anteriorly more distinctly sculptured, without shiny and almost impunctate area; propodeal foramen U-shaped; second submarginal cell less distinctly petiolate.

Comments.

In terms of general morphology, this species is closest to Trigonalys melanoleuca , from which it can be readily differentiated by its color pattern, with frons, most of vertex, and part of gena, reddish brown (vs. black with whitish marks, without reddish brown areas in Trigonalys melanoleuca ); yellow marks at pronotal collar, dorsal margin of pronotum, mesoscutum, scutellum, and metanotum (vs. marks absent); yellow mark at mesopleuron very small and placed dorsad to longitudinal sulcus (vs. large, placed ventrad to sulcus); legs entirely dark brown (vs. with extensive white marks); and yellow marks on propodeum and metasoma less extensive than in Trigonalys melanoleuca . Additionally, Trigonalys melanoleuca has the fore wing more distinctly infuscated, metasomal armature absent, posterior margin of tergum I rounded (vs. nearly straight), propodeum uniformly punctate (vs. laterally areolate, anteriorly coriarious and posteriorly striate) and propodeal foramen always shaped as an inverted U (vs. U- or M-shaped).

The color pattern of Trigonalys erythrocephala is more similar to that of Trigonalys gotica , which is also mostly blackish with yellow marks on the pronotal collar, dorsal margin of pronotum, mesoscutum, scutellum, and metanotum. However, the two species differ markedly in general structure. Trigonalys gotica has a subtle supra-antennal elevation (vs. stout, conspicuous in Trigonalys erythrocephala ); vertex deeply punctate-areolate (vs. moderately punctate); pronotal collar very slightly raised (vs. moderately raised), pronotum with a less evident oblique carina; hind coxa laterally with slight, blunt angles and without strigate area; propodeal foramen V-shaped (vs. U- or M-shaped), and female armature absent (vs. well developed).

Trigonalys erythrocephala can be differentiated from Trigonalys sanctaecatharinae mainlyby the distinct, Y-shaped female armature (vs. delicate, not distinctly Y-shaped) and by the quite different color pattern ( Figs 3 , 20 ).

It can also be distinguished from the other New World species of Trigonalys as follows. Both Trigonalys flavescens Bischoff and Trigonalys maculifrons Sharp have an elongate body, resembling species of Orthogonalys Schulz. Both are also mostly yellow or orange with black marks, including the head yellow with black marks on frons (vs. reddish, without black marks at frons); scutellum yellow with posterior black mark (vs black with sublateral, narrow yellowish lines) and legs mostly yellow (vs. black and dark brown); basal third of tergum I dark brown and remainder yellow (vs. tergum I basal 0.7-0.8 black, apically yellowish). Trigonalys championi Cameron, has the antenna entirely black (vs ferruginous to brown); frons, vertex and gena black (vs. mostly reddish); fore wing entirely violaceous (vs. slightly infuscate, darker at anterior margin); propodeum and petiole mostly whitish (vs. propodeum black with sublateral narrow yellowish marks, petiole mostly black with apical 0.2-0.3 yellowish); and other metasomal segments entirely black (vs. with extensive yellowish marks).

Etymology. From the Greek erythros, red, and cephalon, head, in reference to the somewhat characteristic color of the head capsule.

Figures

Figure 20. Trigonalys sanctaecatharinae (Schulz), lateral habitus (Morphobank accession number M 99949). Picture by David Smith (NMNH).

Figures 3 - 12. Trigonalys erythrocephala Santos et Aguiar, sp. n. Holotype female. 3 Lateral habitus (Morphobank accession number M 90448) 4 Head, antero-ventral (M 90449) 5 Head, antero-dorsal, to show ocelli (M 90450) 6 Head, dorsal (M 90451) 7 Mesothorax, dorsal (M 90452) 8 Propodeum and base of petiole, dorsal (M 90453) 9 Apical segments of metasoma, latero-ventral, left, showing metasomal armature and ovipositor; arrow indicates position of longitudinal carina (M 90454) 10 Pronotum, left (M 90455) 11 Left hind coxa, to show lateral longitudinal carinae (arrows) and dorso-mesal strigation (M 90456) 12 Apical tergites, to show abnormal development of tergites (M 90457).

Figures 1 - 2. Trigonalys melanoleuca Westwood. 1 Lateral habitus. Morphobank accession number (M 99947) 2 Dorsal habitus. Morphobank accession number (M 99948)